Veillonella are gram-negative anaerobic

Anaerobic organism

An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...

 cocci

Coccus

Coccus can be used to describe any bacterium that has a spherical shape. It is one of the three distinct types of bacteria shapes, the other two being bacillus and spirillum cells...

. This bacterium is well known for its lactate

Lactic acid

Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

 fermenting abilities. They are a normal bacterium in the intestines and oral mucosa of mammals. In humans they have been rarely implicated in cases of osteomyelitis

Osteomyelitis

Osteomyelitis simply means an infection of the bone or bone marrow...

 and endocarditis

Endocarditis

Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...

, for example with the species Veillonella parvula

Veillonella parvula

Veillonella parvula is a bacterium in the genus Veillonella. It is a normal part of the flora, but can be associated with disease....

.

Fermentation

Fermentation of lactate to propionate

Propionate

The propanoate or propionate ion is C2H5COO− .A propanoic or propionic compound is a salt or ester of propanoic acid....

 and acetate

Acetate

An acetate is a derivative of acetic acid. This term includes salts and esters, as well as the anion found in solution. Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In...

 is by the methylmalonyl-CoA

Methylmalonyl-CoA

Methylmalonyl-CoA is the coenzyme A linked form of methylmalonic acid. Methylmalonyl-CoA is formed from propionyl-CoA by propionyl-CoA carboxylase by help of biotin . It is converted into succinyl-CoA by methylmalonyl-CoA mutase, in a reaction that requires vitamin B12 as a cofactor...

 pathway. Little ATP

Adenosine triphosphate

Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

is produced in this fermentation. High substrate affinity is suggested to be the reason.

Lactate → acetate + 2 propionate + CO₂ + H₂O